Fuel injection system



L. O. FRENCH FUEL INJECTION SYSTEMl Sept. 1s, 1931.

criginal Filed ual-ch 2s,

Hmfal INVENTOR.

Reissued Sept. 15, 1931 Rie. 18,194

UNITED STATES PATENT" OFFICE LOUIS 0. FRENCH, 0F MILWAUKEE, 'WISCONSIN' FUEL INJECTION SYSTEM Original No. 1,664,615, dated April 3, 1928, Serial No. 97,687, led latch 26, 1928. Application for v reissue tiled Iarch 21, 1930. Serial No. 437,925.

This invention relates to fuel injection systems and more particularly to those systems wherein an electromagnetically-operated fuel-metering device is used to control the amount of fueldelivered to the engine and directly or indirectly control the time at` which such fuel is delivered.

In certain classes of work it is desirable to furnish the same amount of fuel per cycle to the engine cylinder through a wide range offengine speeds, regardless of the change in speed, and thereafter diminish the fuel charge and finall cut ofi` the fuel supply when the speed o the en ine reaches a predetermined maximum. wing to lthe fact that the speed at which fuel is to be supplied in constant amount for each charge may vary several hundred revolutions, it is diflicult to provide a governor-operated switch mechanism to take care of this constant quantity condition through wide ranges in speed, and the object of this invention is to provide cony trol mechanism associated with the control circuit of an electromagneticall -controlled fuel-metering device whereby t e riodic energization of the control magnet or said s device will be substantially constant for a wf fle range of engine speeds and will be modified at higher speeds and to such an extent away vas toprevent the engine exceeding a predetermined maximum speed.

The invention further consists in the several features hereinafter set forth and more particularly defined by claimsat the conclusion hereof.

In the drawings, Fig. 1 is a view of a fuel injection system, parts being shown in detail and other parts shown diagrammatically;

Fig. 2 is a detail sectional view taken on the line 2-2 of Fig. 1, parts being ,broken Fig. 3 1s a view, partly in section, showing a modified form lof part of the control mechanism' Fig., 4 is a detail sectional view taken on the line 4-4 of Fig. 3, together with other `parts of the system shown diagrammatically.

Referring to Fig. 1, the numeral 6 designates a fuel supply tank, 7 a pump, generally engine ydriyen, connectedat its suction side by a pipe 8 with said tank and at its deliver side with a discharge pipe or line 9 whic has a pressure valve 10 mounted therein to maintain the lfuel pressure in the line 9 ata predetermined amount, but which permits excess fuel to return to the tank through a pipe 11.

An electromagnetically-operated metering device instanced here as a control valve 12 is associated With each cylinder 13 of the engine and controls the supply of fuel thereto from a branch pipe 14. This control valve may be of. the type shown in my U. S. Patent No. 1,664,612 dated April 3, 1928, or of any other suitable construction, and its control electromagnet 15 acts upon a valve 16.

The magnet 15 is eriodically energized by passage of current L rough it from a battery 17 or other suitable source of current under the action of circuit control mechanism.

an engine driven distributor brush 24 cooperating with an insulated distributor contact 23 connected in series with the coil of the electromagnet 15 which connects through conductor 21 with ground at 20 While the other side of the battery is connected -by a conductor 25 with a fixed contact 18 while-the contact 19 is shown as grounded at 26. the contacts 18 and 19 are in closed position and the brush 24-is riding over the contact 23, the magnet 15 will be energized and the valve 16 will then be opened to allow fuel to pass to the engine cylinder.

In order that the period during which the contact 18 is in contact with the contact 19 may, through a Wide'speed range, be independent of the engine speed, and may, thereafter, be varied at the higher speeds, I have provided the mechanism shown in Figs. 1 and 2. p

This mechanism includesa shaft 26 driven by the engine and having a timing cam V27 keyed thereto and provided with teeth or projections 28, there being as rnany of these as there are cylinders that may be convenientlysuppliedwth fuel from one control Thus, when mechanism. A hammer member includes a spring 29 anchored at its ends at 30 and curved therefrom as at 31 to a central portion, 32 which carries a curved rojection 33 and a laterally-extending member 34 having an upwardly-extending rojection 35. With this construction, as t e cam 27 turns. in a counter clockwise direction as viewed in Fig.- 1 its lobes 28 successively engage the projection 33 which causes said projection to be moved away from the shaft, thereby bowing the spring 29 outwardly, and directly after each lobe passes said projection'the energy stored up 1n the spring causes it to move to-7 ward the shaft and to some extent beyond its normal position, with the result that the projection 35 delivers a blow to a part 36 of the movable contact.

The part 36 and the spring 37 carrying the contact point 19 are connectedto a s ring 38 secured to a post 39 and form a liexl le support. The part 36, which may be of sheet metal or spring material, has a hook-shaped end 40 which acts as a stop to limit the amplitude of vibration of the'spring 37. When the member 35 strikes the part 36 the other parts aociated therewith are also moved toward vthe sha-ft, with the result that the contact points are engaged and the circuit through the magnet is established. Where the interval of circuit closure is too brief to suit the design or requirements of the engine vthis period may be prolongedby putting a small weight 41 on the outer end of the spring 37 so that the inertia of this weight, after the contacts have closed, will resist the tendency of their contacts to open, as said wei ht has a greater amplitude of movement an thereby tends to move toward the shaft after the contacts are en ed, and will reverse its movement later. glihere such a weight is used a rubber buffer 42, associated with the member 36, may absorb any shock due to a possible rebound of this weighted spring arm.

Inasmuch as the hammer previously referred to always has substantially the same movement, no matter how fast the cam 27 is rotating, the movable contact 19 will remain in contact with-the contact 18 for the same period at all engine speeds under the conditions above described. However, when a certain redetermined s d is reached it is desirab e to decrease t e fuel supply so that the speed of the engine does not exceed a pre-` determined maximum s d, and for this purpose I provide the timing cam with tapered tooth cam portions 43 which are brought into action by a governor that only functions at the higher speeds.

As shown, the cam 27 is slidably mounted on one end of the shaft 26 and secured to a key 44 mounted in a keyway in said shaft4 and connected at its other end to a sleeve 45 slidably mounted on said shaft and within a bore 46 in the hub 47 of a spider 48 iixed to `for rotation relative to the the shaft 26. This spider has arms upon which the levers 49 of the governor are. pivotally mounted, said levers havingforked portions 50 provided with suitable pin projections engaging in an annular groove 1n the upper end'of said sleeve 45 and having weights 52 on their free ends. The shaft 26 is suitably journalled at one point in a bearing 53 carried by a casing 54, and a bearing 53 is provided at the lower end of the casing. A collar 55 is mounted on the shaft 26 and a spring `56 is interposed between said collar and said sleeve. The key 44 is free to move through the inner race of the bearing 53 and the collar 55. The contact supports and the supports for the spring 29 are mounted on a plate 58 which has a tubular hub portion that may be mounted casing 54, `as by providing screws in said hub portion engaging in annular grooves 6 1 ina part 62 of said casing.

Thus, when a predetermined high working speed has been reached the governor starts to function, and as the weighted ends of the le' vers 49 swing outwardly against the action of the spring 56 the sleeve 45, ke 44 and cam 27 are raised upwardly, thus ringing the tapered portion 43 of the teeth into cooperative relation with the projection 3 3 and thus causing the hammer to deliver a lighter blow to the movable contact and producing a briefer and briefer circuit-closing interval for the magnet, thereby cutting down the fuel charge, until finally the speed reaches a maximum and the 'cam no longer strikes the hammer and the fuel supply is Shut off and the engine is thus prevented from exceeding the maximum speed.

When it is not feasible to control the curing under both conditions of operation, I have associated a governor-controlled variable resistance with a constant-period. switch mechanism as shown in Fi 3 and 4 toprovide control mechanism gosr accomplishing the desired result. y

For a further illustration I have shown a constant-period switch mechanism which forV the most part is of well-known construction but which, when longer circuit-closing periods are desired, has1 en modifiedfffrom its usual construction. Briefly, thisjmchanism includes a timing cam 63 mounted upon an engine-driven shaft 64 and engaged by a releasable latch 65...restrained by'a sprmg 66, said latch being moved by said cam perlodically movable contact 69. The part 68u85,y secured to a spring 70, as is also the spring 71 carrying the contact, so that when said hammer strikes the part 68 the contact on the part 71 is moved into engagement with a suitably insulated fixed contact 72. For a more dees lighter and rent supply from a part capable of functionto deliver a blow against a pivotedhammer 67 which in turn strikes a partg'fofthe l tailed explanation off this type ofswitch mechanism reference is `made to lUnited States Letters Patent No. 1,246,818, to A. A. Kent, it beingunderstood that this switch structure is selected as an example of one form of switch mechanism that may be used' 'period', asexplained above in connection with the part 37 and the weight 41.

76 inthe hub of a spider 77 fixed' to said shaft. This spider has arms upon which the levers 78 of the governor are pivotally mounted, said levers having forked portions 79 provided with suitable pin projections V80 engaging in, the annular groove 81 ofsaid sleeve and having weights 82 on their free ends. The shaft 64 is suitably journalled in the upper end of the casing 83 and a bearing 84 is .provided atv the lower end of the'casing.

` A collar 85 is mounted on said shaft and a a lever whose shaft 94 .is pivotally mounted on the casing. This lever has a switch arm 95 suitably insulated from the pivot',shaft lses and receiving current from abrush 96. The arm 95 engagesv or rides over a reslstance element 97 spirallylwound upon a'suitable insulating support. A stop in 77 is associated with a slot 74 to limltthe movement of the sleeve 74. i

With this construction, after a 'predetermined high speed has been attained by the engine the governor starts to raise the sleeve 64 and this swings'the lever 93 and hence the arm 95, causing ithto include more and more resistancein the control circuit, -and this hasthe effect of gradually decreasing the duration of movement of the fuel-ineterin device until finally when a predetermined maximum speed has been reached the included resistance is so great that the strength of current furnished to the electromsgnet is insufficient to lift the control valve an hence the fuel supply is cutoff and the engine slows down to a point below maximum speed.

A circuit arrangement is shown in Fig. 4,

wherein the movalhle contact 69 is grounded at 99'and a conductor 100 connects thecontact 72 with the brush 96, and a conductor 101 connects one'end of the resistance element97 with the distributor brush 24 which mined maximum s lis actuated by the engine to periodically engage the distributor contact 23 connected by a conductor 22 to one terminal of the operating electromagnet of the control valve 12, the other terminal of said operating magnet ofthe valve. 12 being to ground as shown in Fig. 4. The battery 17 is shown as connected in between portions of the conductor 100'. Thus, during the period the contacts 69 and 70 arey engaged the brush 24 is engaged with one of the distributor contacts and current `is supplied to the 'electromagnetic valve associated with that Contact and is controlled as Referring to Fig. 3, a sleeve 74 is sl1dablymounted onthe shaft 64 and within a bore.-

above described.

It is to be noted that the plate 58 carrying the contacts 18 and 19 may be rotated rela- .tive to the cam 27 to vary the time in the cycle at which the contacts are engaged and thus the time of injection may be advanced or retarded. Similarly the member 102, similar to the member 58 and upon which the contacts 69 and 72 are mounted, may be adjusted angularly relative to the cam 63 to advance or retard the time of injection. Furthermore, an automatic advance may be associated with the cam 63 in known manner.

While the invention has been described more particularly in connection with an electromagnetically-controlled fuel-metering valve, it will be understood that any other suitable metering device may .be asso-, ciated with the electromagnet, in combination, withthe control means above described, and be within the scope of the appended claimsf I desire it to be understood that this invention vis not to be limited to any particular form or arrangement ofv parts except in so far as such limitations are specified in the claimsornecessitated by the prior art.

What I claim as my invention is:

1. `In a fuel injection system, the combination of a fuel-metering device, an electromagnet for controlling said device, and a control circuit for said electromagnet including means inuencing the current supply to said magnet to actuate said device to supply substantially constant quantity fuel charges through a Apredetermined range of engine speeds and thereafter decreasing the amount of fuel vabove a predetermined engine speed and cutting off said fuel supply at a predeter- 2. In a fuel injection system, the combinal tion of a fuel-metering device, an electromagnetfor controlling said device, and acontrol circuit Afor saidV electromagnet including means for periodically energizing said magnet` for substantially constant periods through amount of fuel charge and to cut off said. .fuel

' wide range of engine speeds, and a governor,

suppl at a predetermined'maximum'speed.

3. 1in a fuel injection system, the combination of a fuel-metering device, an electro- II ma et for controlling said device, a, contro circuit for said electromagnet including switch mechanism for periodically-energizing said magnet 'zfor substantially constant periods at' different engine speeds, a governor, "'and 'means ,co'ntrolled b said governor, for

-modifying the action o said 'switch'mecha- .nism above a predetermined speed to'decrease thezfuel supplylto the .engine and to cutoff said uel supply at a predetermined maximum spee.-

4. In a fuel injection system, the combination of a fuel-metering device, an electromagnet ,for controlling said device, a control `circuit for said electromagnet including switch mechanism for periodically energizing said magnet for.substantial1y constant periods at different engine speeds, an enginedriven cam for actuating said switch mecha? nism, a governor,andv means, controlled by :the governor, to shift said cam to modify the action of said `switch mechanism above a redetermined speed to thereby decrease the fuel supply to the engine and to cut olf said fuel supplly at a predetermined maximum s d.

5. n a fue injection system, the com ination. of 'a fuel-metering device an electro- Ymagnet for controlling said device, a. control circuit for said electro a et including switch mechanism for 'periodi1 ing said magnet for substantiall .periods through a predetermin constant range of en ine speeds, and a governor-controlled varia le resistance operable above a prede- -termined speed to decrease the fuel supply to the engine and to cut off said fuel supply at a predetermined maximum speed.

' 6. In a fuel injection system, the combination of a fuel-metering device, an electroy .magnet for controlling saiddevice, a con trol circuit for said electromagnet including switch mechanism comprising a fixed and a movable contact, a hammer'member for ac.

tuating said movable contact, a shiftable en ine-driven timing cam .foryactuating'said ammer member, anda governor, operable .above a predetermined-engine speed, to shift said cam to vary its action on said hammer member to decree the fuel supply and to render said .hammer member inoperative above a predetermined maximum speed.

tion of 4ajfuel-metering device, an'electromagnet for controlling said device, a control circuit for said electromagnet includingV cally energizpredetermined speed ran e.

7. In a fuel injection system, the combinai constant circuit-closing periods through a movable. contact and a-weight associated with said movable contact .to prolong its circuit- Vclosing period over that imposed upon it by '.'said actuating means.

9. In a fuel injection system, the combination of a fuel-metering device, an electromag- :Iiet for'controlling said device, and a controlt circuit for said electromagnet including .means for periodically influencing the current supply to said magnet -for substantially constantperiods to actuate said device to supply .substantially constant quantity 'fuel 00 charges through aA predetermined range of engine speeds regardless-of such speeds.

10. In al fuel injectionl system,r the combination of a fuel-metering device, an electromag- 'net for controlling said device, and a controlj 95 circuit for said electromagnet including means for. riodically energizing said electromagnet r substantially'constant periods through a predetermined range. of engine speeds to cau'sepsaid-dvice to su ply sub- '100 stantiallyconstant quantity fuelc arges at thesespeeds.- 11. In a fuel injection system, theA combination of a fuel-metering device, an electromagnet for controlling said device, anda control s1-05 circuit for said electroma et including means for periodically energizing said magnet for substantially constant periods through a predetermined range of engine speeds to cause said device to supply substantially constant quantity fuel charges at these speeds, a governor controlled l mechanism operable above a predetermined' range influencing the current supply to said magnet to decrease,` the amount of fuel charge above a.

In testimony whereof, 'aix msi ature.

. LOUISv O. F E CH.

and adapted to engage an actuate Said movable contact, 'a shiftable engine-driven dam for 6'5. 'said hammer member to 'provide 

